Improvement in the manufacture of white lead



.To all whom it `may concern:

UNITED.- STATES- PTENT OFFICE.

cHAnjnnsDwnLna-or Sr. Louis, MISSOURI;

y l IMPROVEMENTJI THE IMANUFACTUREOF wHlTE LEAD.

` Speciflcationforming part Aof Letters Patent No.195g097, dated September 2l, 1869.

Be it known that l, CHARLES W. DWELLE, of the city of St. Louis, in the county of St. Louis and State of Missouri, have made certain new and useful Improvements-in Processes for Manufacturing Vhite Lead and Similar Substances; and I do hereby ldeclare the foll lowing to be afull and true description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

It is well known that usually metalli@ lead is subjected to the action o f carbonio acid in dung-heaps and similar carbonio-acid generators, whereby carbonate of leadis formed. The incrustated salt is'then by shaking and sifting devices removed from such metallic lead as may be still remaining unacted upon; and

.in the usual process of separation the dust of the carbonate is deleterious to health and very difficult of economical manipulation.

For the purposes of a more complete separation of the carbonate, and to avoid wzl-stage of the same,vthe nature of this invention is in the arrangement of a fan or other suction and forcing device by which the carbonate-dust shall be carried ol from the reel or other separator device, and by which said carbonate shall be forced either into proper bags or into watertanks, asreceivers and accumulators therefor; and thenature of this invention is also in the entire arrangement and conjoined action of the various crushing, separating, and elevating l devices tobeusedin the process of manufacture of white lead and similar substances, as will now be more fully explained.

To enable those herein skilled to make and use my said improved process and devices, I will now fully describe the same, referring to the accompanying Figure l as a longitudinal sectional elevation; to Fig. 2 as a transverse sectional elevation, showin g the devices acting in my said process in one of the more usual forms of its application.

The carbonated-leadcakes or buckles will be received at the base of an e1evator,'A.' Said elevator will have conveyer-buckets arranged, in the usual manner upon an endless belt and 'operated from the power` source, so as to carry the carbonate to an upper funnel and discharge the same to thewreel B. This will be formed principally of a metal drum with proper perforations, revolving upon a shaft actuated by proper-machinery -By the revolution otl the Vreelthelcarbonate is Separated from such lnetallicllead asmay stillbe in the cakes, and said carbonate will-passthrough the perforations of the reel into the surrounding hopper B'. In connectiorl with said hopper is thefan G, formed of a number of fan-blades, which are rapidly rotated upon a shaft in the usual manner. By the suction thus created the linerV particles of the carbonate will be drawn to the fan out of the hopper B', to be then carried up the rising pipe D to the distributing-pipe E, usuallyV arranged at the top of the building. Said distributing-pipe E may be connected with bags F, into which the carbonate will fall, or the said pipe maylead to acistern, G,partially filled with water, for receiving and retaining the carbonate. To prevent loss by the efflux of the air from the water in the cistern G, I arrange a pan, G', near the top hereof, said pan being perforated and receiving theWater-supply directly from the supply-pipe. The air will then escape by the annular space between the vertical rim of the pan Gr' and the cisternwall. To arrest any dust which might pass here there is a ring, g, curving downward, placed over said annular space as acover, as more plainly shown in Fig. 1. The heavier particles of carbonate and metallic lead drop into the trough at the base of the hopper B', to be carried forward by a conveyer-screw or similar device, B2. The metallic lead not passing through the reel-drum B will be deposited at the tail of the reel upon the floor, to be used with'new lead in the ordinary processes. The carbonate delivered from the conveyer-trough falls by the spout H tothe rollers I, which, by their revolution, crush and pulverize as well as thoroughly separate out the remaining metallic particles. From said rollers the product is carried by the spout K to a second reel or separator, L. This, as it f l receives less of 4the heavy metallic substance, may be built of a light frame, surrounded by a bolt or other screening wire-cloth. By'this separator the metal is again thrown out, principally as tailings, while the li'ght carbonatedust is carried out of the inclosing hopper by a fan or other similar device, M, to be distributed to the bags F or thecistern G, as described. Such droppingsas are too heavy for distribution bythe fan drop to the trough and conveyerscrew M', to be carried to the base of an elevater, N, whichraises said droppings to a funas to unt it for respiration.

nel, 0, to be delivered c second time to the rollers I for pulverization.

It is plain that the operator may by proper management cause` the carbonate and its ad mixtures to pass repeatedly to the crushingrollers and separators, and thus fully separate out all the carbonate without Wnstage or undue loss, and that in all said process the carbonate dust is fai rl y inclosed and shielded from loss as Well as from detrimental action upon the op eratives. Lastly, it is especially the finer cer* boncte-dust which, by its reduced relative spe cic gravity and hulk, that, is here subject to the action of the fans C and M, end which is therefore carried forward to the receivers, while in ordinary processes this finer dust evedes all e'orts to its retention, and vitictes the air so Having thus fully described my invention, what I claim is- CEAS. W. DWELLE.

Witnesses:

Gmo. P. HERTHEL, J r., WILLIAM W. HERTHEL. 

